Film Material For Air Filled Packing Cushions

ABSTRACT

A machine which inflates and seals pillows in packaging is compact in overall size, can be conveniently operated to produce varied lengths of strips of inflated pillow-type packaging as needed, can begin production of inflated pillow-type strip packaging immediately after being held out of a production cycle for some period of time, and applies a heated sealing element directly to and in sliding contact with a web of film to securely seal the inlet port of an inflated pillow while the pillow is under pressure and as the web of film is continuously and uninterruptedly advanced through the machine.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division of application Ser. No. 11/186,849, filed Jul. 22,2005, which is a continuation of application Ser. No. 10/366,812, filedFeb. 13, 2003, which is a division of application Ser. No. 10/108,823,filed Mar. 26, 2002, now U.S. Pat. No. 6,605,169, and a division ofapplication Ser. No. 09/638,843, filed Aug. 14, 2000, now U.S. Pat. No.6,659,150, which in turn is a continuation-in-part of application Ser.No. 09/439,552, filed Nov. 12, 1999, now U.S. Pat. No. 6,209,286, whichclaims priority under 35 U.S.C. § 119(e) to Provisional Application No.60/123,497, filed Mar. 9, 1999.

BACKGROUND OF THE INVENTION

This invention relates to methods and apparatus for inflating andsealing pillows in packaging.

This invention relates particularly to the construction and operation ofa machine which is small enough to be installed for operation on sitewhere articles packaged for transport are placed in shipping containerswith protective inflated pillow-type strip packaging.

This invention relates particularly to a machine which is compact inoverall size, which can be conveniently operated to produce variedlengths of strips of inflated pillow-type packaging as needed, which canbegin production of inflated pillow-type strip packaging immediatelyafter being held out of a production cycle for some period of time andwhich applies a heated sealing element directly to and in slidingcontact with a web of film to securely seal the inlet port of aninflated pillow while the pillow is under pressure and as the web offilm is continuously and uninterruptedly advanced through the machine.

This invention relates particularly to a machine which forms the sealcomplete and secure during a short path of travel and during a shortinterval of time. The seal is made without the need for additionalpressing together of the film after the sealing and without the need foradditional cooling of the seal after the sealed inlet port moves out ofcontact with the sealing structure.

Webs of plastic film which are constructed to permit the production ofstrips of air filled envelopes, cushions and pillows have (in the pastten years or so) been used extensively for cushioning objects to betransported in containers.

The thin webs of plastic film are inexpensive, tough, resilient andrecyclable. Strips of inflated pillow packaging which are created fromthese webs of plastic film are used for void-fill packaging to replaceproducts such as crumpled paper or polystyrene peanuts and forprotective packaging to replace molded or extruded foams.

U.S. Pat. No. 5,454,642; U.S. Pat. No. 5,651,237; U.S. Pat. No.5,755,328; U.S. Pat. No. 4,017,351; and U.S. Pat. No. 5,824,392 disclosemethods, apparatus, and webs of plastic film used for making strips ofinflated pillow packaging of this general kind. Each of these U.S.patents is incorporated by reference in this application.

U.S. Pat. Nos. 6,116,600 and 6,209,286 also disclose methods, apparatusand webs of plastic film of this general kind and are incorporatedherein by reference.

Sealing an inflated pillow made a web of plastic film while the airinflates the pillow under pressure and while the web of plastic film isbeing transported through the machine presents problems.

The seal must be secure and must not leak in order for the inflatedpillow packaging to be used effectively for cushioning objectstransported within a container.

The seal needs to be formed efficiently, quickly and without extensive,related pressing and/or cooling structure in order to make the machineas compact as possible in size and as efficient as possible inproduction rate.

To simplify machine construction and to provide a high efficiency ofproduction, it is desirable to be able to make the seal as the web ofplastic film is moved continuously and without any interruption and/orintermittent stopping of the film transport during the sealingoperation.

It is a primary object of the present invention to construct and tooperate a machine which is compact in size, which is efficient inproduction, which is continuous and uninterrupted in operation and whichproduces seals which are secure and which do not leak.

SUMMARY OF THE PRESENT INVENTION

In a specific embodiment of the present invention, a machine inflatesand seals pillows in packaging while continuously and uninterruptedlyadvancing a web of film through an inflating station and a sealingstation. The inflating station sequentially inflates pillows atpreformed patterns in the web of film by introducing pressurized airthrough a narrow width inlet port of a preformed pattern. The sealingstation seals each inlet port by applying a heated sealing elementdirectly to and in sliding contact with the web of film while the air inan inflated pillow is under pressure as the inlet port moves across theheated sealing element.

The web of film has an uninflated pillow pattern and an uninflatedinflation channel preformed in the film. The uninflated pillow patternscomprise multiple, spaced apart, pillow patterns aligned along one sideof an inflation channel. The inflation channel extends longitudinallyand continuously along the entire length of the film. Each uninflatedpillow pattern has a narrow width inlet port extending generallytransversely to the longitudinally extending inflation channel andconnecting the uninflated pillow pattern to the uninflated inflationchannel so that, when pressurized air is introduced into the inflationchannel, the pressurized air can be transmitted through the inlet portto inflate the pillow pattern. In some cases the preformed pattern isalso formed with outlet ports connected to the inflation channel in sucha way that air entering the inflation channel can move into a pillowthrough an inlet port and can also exit out of the inflation channelthrough the outlet port. The outlet port is generally shaped smallerthan the inlet port.

By allowing the air above a desired pressure to escape through an outletport or ports, the pressure in the inflation channel is maintained at adesired level for inflating the pillows creating over-pressurization.

The air escaping through the outlet port is also sensed to detect wherethe pillows are in the machine. These detected outlet port positions arethen used as signals for an associated electronic unit to count thenumber of pillows inflated in a particular run through the machine. Thisalso facilitates being able to stop the movement of the film through themachine after one production run of a selected number of inflatedpillows at a position which is the right position to start a subsequentproduction run of a selected number of inflated pillows.

In a specific embodiment of the present invention, the web of film withthe preformed patterns is stored on a storage roller of the machine andis advanced through the machine by a first set of nip rollers and asecond set of nip rollers at a respective first film transport stationand a second film transport station.

Pressurized air is introduced into the inflation channel of the web offilm at an inflating station as the web of film is transported throughthe first film transport station. The pressurized air inflates at leastone of the pillow patterns prior to the time the web of film iscontinuously transported through a sealing station.

Pressure is maintained in the inflated pillow pattern within acalibrated pressure range during the time that the web of film iscontinuously transported through the sealing station.

At the sealing station the inlet port of an inflated pillow is sealed byapplying a heated sealing element directly to and in sliding contactwith the web of film. The heated sealing element slides across the inletport while the air in the inflated pillow is under pressure and as theweb of film is continuously and uninterruptedly advanced throughout allcomponents of the machine.

The heated sealing element has a relatively small longitudinal dimensionin the direction of movement of the web of film. In a specificembodiment the length of the heated sealing element is about the same asthe width of the inlet port of a pillow pattern. This small size of theheated sealing element helps minimize the amount of sealing heat appliedto the web of film.

The sealing station includes a sealing roller disposed alongside theheated sealing element so as to permit the web of film to be advancedbetween the sealing roller and the heated sealing element. Adjustablebiasing means provide for adjustment of the force with which the heatedsealing element and the sealing roller are pressed toward engagementwith one another.

The sealing roller is positioned with respect to the first and secondpairs of nip rollers so as to cause the web of film to wrap around apart of the peripheral surface of the sealing roller both in acircumferential direction and also in a lateral direction. This helpscreate a dead and flat zone right at and adjacent to the line of sealingacross the inlet port. This in turn facilitates making a secure sealwithout leaking while the pillow is inflated under pressure.

The axes of rotation of at least the second pair of nip rollers arepreferably canted at a slight angle with respect to the axis of rotationof the sealing roller.

The second pair of nip rollers are preferably rotated at a speedslightly faster than the speed of rotation of the first pair of niprollers so as to maintain tension in the web of film between the secondand first pair of nip rollers.

In one specific embodiment of the present invention the heated sealingelement is a fabric covered Nichrome wire disposed at the end of a barelement which is biased toward engagement with a sealing roller. Thefabric covering of the Nichrome wire has a Teflon coating on its outersurface for facilitating sliding of the heated sealing element on theengaged surface of the film as the web of film is advanced through themachine.

The bar on which the heated sealing element is mounted is a compositebar. The very tip of the bar is a ceramic having good insulatingqualities, and the remainder of the bar is a different material selectedto provide enhanced mechanical durability.

The seal is formed complete and secure during a short path of travelthrough the sealing station.

The seal is complete and secure at the time the web of film moves out ofcontact with the wheel at the sealing station and without the need foradditional pressing together of the film after the sealing station andwithout the need for additional cooling of the film across the sealedinlet port after the sealed inlet port moves out of contact with thesealing station.

In a second specific embodiment of the present invention the sealingwheel is pressure biased toward engagement with the heated sealingelement.

In both the first and second specific embodiments the heated sealingelement and the sealing wheel are spaced apart from one another when themachine is not transporting the web of film through the machine in aproduction run. This enables the heated sealing element to be maintainedat a desired temperature level while preventing contact with andpossible burning of the unmoving film at the sealing station.

In one specific embodiment of the invention the fabric covering for theNichrome wire is held in a fixed position at the end of the bar elementand is replaced as needed.

In another specific embodiment of the invention the heating stationincludes a cartridge unit which can be quickly and easily interchangedwith another cartridge unit. The cartridge unit includes an elongatedstrip of the fabric covering. The strip is mounted on two rotatablereels. The fabric always covers the Nichrome wire, as in the firstspecific embodiment, and the fabric has a Teflon coating on the sidewhich engages the film in sliding contact, as in the first specificembodiment. The elongated strip of fabric covering is wound between thetwo reels so as to be moved across the length of the Nichrome wire at aspeed which is much slower than the speed of movement of the filmthrough the machine but which is fast enough to ensure that the coveringstrip of fabric is always effective to function properly without anyburn through of the fabric or damage to the film from the heatedNichrome wire. The cartridge unit permits the Nichrome wire of theheated sealing element to be easily disconnected from its power supply.The cartridge units are constructed to be readily interchanged as units,rather than having to replace individual components of the cartridgeunit.

Methods and apparatus which incorporate the features noted above andwhich are effective to function as described above comprise further,specific objects of this invention.

Other and further objects of the present invention will be apparent fromthe following description and claims and are illustrated in theaccompanying drawings, which by way of illustration, show preferredembodiments of the present invention and the principles thereof and whatare now considered to be the best modes contemplated for applying theseprinciples. Other embodiments of the invention embodying the same orequivalent principles may be used and structural changes may be made asdesired by those skilled in the art without departing from the presentinvention and the purview of the appended claims.

BRIEF DESCRIPTION OF THE DRAWING VIEWS

FIG. 1 is an isometric view of a machine, constructed in accordance withone embodiment of the present invention, for inflating and sealingpillows in packaging. FIG. 1 is a general view which illustrates how aweb of film is transported through the machine. FIG. 1 shows how the webof film has a preferred pattern of spaced-apart, inflatable pillowsaligned along one side of a longitudinally extending inflation channel.FIG. 1 illustrates how rollers (at a first transport station, at asealing station, and at a second transport station) are positioned toengage the underside (as viewed in FIG. 1) of the web of film.

FIG. 2 is another isometric view of the machine shown in FIG. 1, but inFIG. 2 the lower part of the figure has been revised to (in effect) seethrough the web of film in order to show details of certain structure ofthe machine. FIG. 2 shows the inflation tube of the inflating action,the nip rollers of the first transport station, the heated sealingelement and the associated sealing roller at the sealing station, andthe nip rollers at the second transport station.

FIG. 3 is an isometric view of the machine of FIGS. 1 and 2, but withoutthe web of film material. FIG. 3 shows the main structural and operativefeatures of the machine itself.

FIG. 4 is an isometric, enlarged view showing details of the features ofthe first film transport station, the inflation station structure, thesealing station structure, the slitting station structure, and thesecond film transport station structure.

FIG. 5 is an isometric, enlarged view like FIG. 4 but shows details ofjust the mechanism for driving the various rollers of the machine. FIG.5 does not show the inflation station structure, the heated sealingelement at the sealing station, or the slitter structure for opening upthe inflation tube of the web of film after the sealing station.

FIG. 6 is an isometric view showing details of the structure of thesealing station. FIG. 6 shows the heated sealing element pressed towardengagement with the sealing wheel in the positions occupied by those twocomponents during a production run of the inflated pillow packagingthrough the machine.

FIG. 7 is a top plan view, taken along the line and in the directionindicated by the arrows 7-7 in FIG. 6, but showing the heated sealingelement retracted away from the sealing wheel in the positions occupiedby those two components when no film is being transported through themachine.

FIG. 8 is a top plan view of a specific embodiment of a web of filmconstructed in accordance with the present invention and having aspecific pattern of inflatable pillows, inlet ports for permittinginflation of the pillows, and escape ports for preventing overpressurization of the pillows and for also permitting more accurateposition sensing of the pillows as the web of film moves through themachine.

FIGS. 9A-9G are a series of the isometric views showing details of thestructure, components and sequence of assembly of certain components ofthe heated sealing element at the sealing station.

FIG. 10 is an isometric view of a machine constructed in accordance witha second embodiment of the present invention. The embodiment of themachine shown in FIG. 10 includes a cartridge unit which is mounted on aseparate sub-plate or sub-frame and which permits all of the componentsof the cartridge unit to be quickly and easily removed and replaced byanother, replacement cartridge unit. The cartridge unit provides theheated sealing element components for the sealing station. FIG. 10 showsthe sealing wheel of the sealing station positioned to engage the web offilm in sliding contact with the heated sealing element during aproduction run of packaging.

FIG. 11 is an isometric view like FIG. 10 but showing the sealing wheelmoved to a retracted position which permits the web of film to move outof contact with the heated sealing element when the machine is stoppedbetween production runs and the film is not being transported throughthe machine.

FIG. 12 is an enlarged, isometric view of the replaceable cartridge unititself. FIG. 12 shows the strip of covering fabric in stored positionson the reels of the cartridge unit prior to installation of thecartridge unit in the machine. When installed in the machine, a portionof the strip of covering fabric is positioned over the wire of theheating element (as illustrated in FIGS. 10 and 11).

FIG. 13 is an enlarged, isometric view of the sealing wheel and therelated actuator mechanism for positioning the sealing wheel at thesealing station.

FIG. 14 is an enlarged, side elevation view of the sealing stationstructure with the structure in the operative position shown in FIG. 10;and,

FIG. 15 is an enlarged, side elevation view of the sealing stationstructure with the structure in the non-operating position shown in FIG.11.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1, 2 and 3 are isometric views of a machine, constructed inaccordance with one embodiment of the present invention, for inflatingand sealing pillows in packaging.

The machine is indicated by the general reference numeral 11 in each ofFIGS. 1, 2 and 3.

The machine 11, as most easily viewed in FIG. 3, comprises a main plate13 on which various structural and operational features are mounted.

A support tube 15 is mounted at the upper (as viewed in FIGS. 1-3) ofthe main plate 13 for supporting a roll 17 of a web of film 19 (seeFIGS. 1 and 2).

Guide tubes 21 and 23 are mounted on the plate 13 below the tube 15. Thetubes 21 and 23 serve to guide the web of film 19 from the roll 17 tothe operating mechanism 25 of the machine 11. The operating mechanism 25is described in more detail below.

The mechanism 25 is illustrated in detail in FIG. 4 and comprises afirst film transport station 27, a second film transport station 29, aninflating station 31, a sealing station 33, and a slitting station 35.

The first film transport station 27 includes a first pair of nip rollers37 and 39 for gripping the web of film 19 (see FIG. 1) and for pullingthe web of film 19 from the roll 17 and under and over the guide tubes21 and 23 and through the first film transport station 27 when the niprollers are rotated by associated drive gears 41, 43 and a drive belt45. The nip rollers 37 and 39 are rotated in the directions indicated bythe direction arrows on the drive gears 41 and 43 shown in FIG. 4.

The drive belt 45 is driven by a drive gear 47 which is in turn drivenby a motor 49 (see FIG. 5).

The second film transport station 29 comprises a second pair of niprollers 49 and 51 which grip the web of film 19 to continuously advancethe web of film 19 from the first transport station 27 to and throughthe inflating station 25 and to and through the sealing station 33 andthen to and through the second film transport station 29.

The nip rollers 49 and 51 are driven by drive gears 53 and 55 and in therotational directions indicated by the directional arrows on the drivegears 53 and 55 in FIG. 4.

Drive shafts 40 and 44 transmit the drive from the drive gears 41 and 43to the nip rollers 37 and 39.

Drive shafts 50 and 52 transmit the drive from the drive gears 53 and 55to the nip rollers 49 and 51.

With continued reference to FIG. 4, the drive belt 45 passes about anidler gear 57. The drive gears 41, 43, 47, 53, 55 and idler gear 57 areall mounted for rotation on and are supported by the main plate 13.

The inflating station 31 includes an inflation tube 59 and a generallyspherically shaped and partially Teflon coated ball 61 located at theupper end (as viewed in FIG. 4) of the tube 59. The ball 61 has aplurality of openings 63 for injecting pressurized air into an inflationchannel in the web of film 19.

As illustrated in FIGS. 1, 2 and 8, the web of film 19 as stored on theroll 17 shown in FIG. 1 has a pattern of pillows 65, a longitudinallyextending inflation channel 67, inlet ports 69, and outlet ports 71preformed in the web of film. The pillows 65, channel 67, ports 69 andports 71 are uninflated in the web of film as stored on the roll 17.

The uninflated pillow patterns 65 are longitudinally spaced apart fromone another and are aligned (in the embodiment of the web of film 19illustrated in the drawings) along one side of the inflation channel 67.

The inflation channel 67 extends longitudinally and continuously alongthe entire length of the web of film 19.

The inflation channel 67 is dimensioned to provide a close, sliding fitover the Teflon coated ball 61.

Each pillow 65 is connected to the inflation channel 67 by an inlet port69. The inlet port 69 extends generally transversely to thelongitudinally extending inflation channel 67 and has a narrow interiorwidth which is positioned at the sealing station 33 (in a manner to bedescribed more fully below) to facilitate quick and secure sealing ofpressurized air within an inflated pillow 65 in a small path of traveland in a short time of continuous, uninterrupted travel through thesealing station 33.

The outlet ports 71 are shaped to be somewhat smaller than the inletports 69. These outlet ports 51 are located on the side of the channel67 opposite the inlet ports 69 and are generally aligned with the inletports 69.

As will be described in greater detail below, the outlet ports 71 allowair to escape in a way to maintain pressure in the channel 67 and in theinflated pillows at a calibrated, desired level without creatingover-pressurization in the pillows.

In addition, the air that exists from an outlet port 71 can be sensed bya pressure transducer 73 (see FIG. 8) to allow for accurate positionsensing of the pillows as the pillows move through the machine 11.

The air escaping through the outlet ports is sensed to detect where thepillows are in the machine. These detected outlet port positions arethen used as signals for an associated electronic unit to count thenumber of pillows inflated in a particular run through the machine. Thisalso facilitates being able to stop the movement of the film through themachine, after one production run of a selected number of inflatedpillows, at a position which is the right position to start a subsequentproduction run of a selected number of inflated pillows.

The upper end of the inflation tube 59 is formed with a small curvatureso as to better follow the path of the film 19 as the film is advancedthrough the first transport station 27 and the sealing station 33.

Details of the construction and mode of operation of the sealing station33 are illustrated and will be described with reference to FIGS. 4, 6and 7.

The sealing station 33 comprises a sealing roller 75 mounted on a shaft77 which is in turn mounted for rotation in a bearing assembly attachedto the main plate 13.

The sealing station 33 also comprises a heated sealing element locatedat the outer end (the right hand end as viewed in FIG. 7) of a bar 81.The very tip 80 of the bar 81 is a ceramic of aluminum silicate toprovide an insulation function, and the remainder of the bar 81 is adifferent material selected for mechanical durability.

The bar 81 is mounted for sliding motion within a support 83.

A spring 85 and an adjustment screw 87 provide a selectable bias forcefor biasing the bar 81 toward the opposed periphery of the roller 75 sothat the film 19 (in the longitudinally extending strip which crossesthe inlet ports 69) is pressed in rolling contact with the outerperiphery roller 75 and in sliding contact with the end surface of thebar 81 as the first and second film transport stations continuouslyadvance the web of film 19 through the sealing station 33.

An actuator 89 is included in the sealing station 33 for retracting thebar 81 against the bias of spring 85 and away from engagement with theroller 75 when the film 19 is not being advanced through the machine 11.This facilitates keeping the heating element energized at the properheating level and out of contact with the film 19 during time intervalswhen the machine 11 is not being used to produce inflated pillowpackaging.

Details of the structure, components and sequence of assembly ofcomponents of the heated sealing element are shown in the exploded viewsof FIGS. 9A-9F.

The heating element disposed at the end of the bar 81, in a specificembodiment of the present invention, comprises at least one Nichromewire 70 which runs vertically (as viewed in FIGS. 9A-9G) along the righthand end of the bar 81.

The Nichrome wire 70 at this location has a length about the same as thethroat width of an outlet port 69 in the film 19, and the Nichrome wire70 is covered by a fabric 72 having a Teflon coating on the surfacewhich contacts the film 19. The fabric covering 72 helps to form thewire 70 to a preferred shape for engagement with the film 19, and theTeflon coating facilitates sliding movement of the film 19 with respectto the heated sealing element.

The heated sealing element comprises at least one Nichrome wire 70, but(as illustrated in FIGS. 9A-9F) the present invention also encompassesusing a plurality of parallel extending and laterally spaced apartNichrome wires 70 for providing multiple seal lines across inlet ports69 of the pillows 65.

As best illustrated in FIGS. 6 and 7, wires 91 and 93 conductelectricity to the Nichrome wire for heating the Nichrome wire.

The slitting station 35 (see FIG. 4) includes a blade 95 attached to theinflation tube 59 and positioned to slit the inflation channel 67 in thefilm 19 after the outlet port 69 of a pillow 65 has been sealed at thesealing station 33. This enables strips of inflated packaging to beremoved from the machine 11.

It is an important feature and benefit of the present invention that thecomponents of the mechanism 25 and the coaction between those componentsenable a seal to be formed complete and secure in a short path of travelof the film through the sealing station 33 and in a short period of timeand without the need for additional pressing together of the web of filmafter the sealing station and without the need for additional cooling ofthe seal across the inlet port after the sealed inlet port moves out ofcontact with the sealing station. The sealing of the inlet port at thesealing station is performed by applying the heated sealing elementdirectly to and in sliding contact with the web of film and across theinlet port while the air and the inflated pillow is under pressure andas the web of film is continuously and uninterruptedly advanced throughthe mechanism 25 shown in FIG. 4.

A number of features of the present invention contribute to obtainingthis efficient and beneficial sealing result.

As described above, the outermost tip of the bar 81 is a ceramicmaterial which functions as an insulator to help confine the heat of theheating element to substantially just the linear area of contact of thefabric covered Nichrome wire with the film 19.

The roller 75 is laterally offset outwardly (as viewed in FIGS. 1-5) andis positioned with respect to the pairs of nip rollers 37-39 and 49-51so as to cause a bump in the film 19 at the sealing station 33. Thishelps to create a dead zone adjacent the inlet port 69 to be sealed bycausing the web of film 19 to wrap around a part of the peripheralsurface of the sealing roller 75 both in a circumferential direction andalso in a lateral direction.

Driving the second pair of nip rollers 49-51 at a slightly higher speedthan the first pair of nip rollers 37-39 helps to insure that the film19 is maintained flat and in substantially pressure sealing engagementwith the periphery of the sealing roller 75.

As best shown in FIG. 5, the axes of rotation of at least the second setof nip rollers 49-51 are preferably canted at a slight upward (as viewedin FIG. 5) angle with respect to the axes of rotation of the main drivegear 47 and the sealing roller 75.

In a specific embodiment of the present invention the axes of rotationof the first set of nip rollers 37-39 are also canted at this sameslightly upwardly inclined angle.

The inclusion and positioning of the outlet ports 71 (see FIG. 8) andthe smaller size of these outlet ports contribute to allowing air toescape through the outlet ports in an amount to maintain sufficientpressure in the channel 67 without permitting over-pressurization inthat channel 67 or in the pillows 65.

The present invention permits sealing the inlet port at a sealingstation by applying a heated sealing element directly to and in slidingcontact with the web of film and across the inlet port while the air andthe inflated pillow is under pressure and as the web of film iscontinuously and uninterruptedly advanced through each of the firsttransport station, inflating station, sealing station, second transportstation and slitting station.

In FIGS. 1, 2 and 8 of the drawings the pillows 65 are shown in agenerally rectangular-shaped pattern. It should be noted, however, thatthe pillows 65 can be any preformed pattern configuration. The patternsof the pillows 65 can, for example, include preformed seal line elementswithin the interior of the pillows which permit the pillows to be foldedalong one or more of the preformed interior seal lines. This in turnpermits one pillow to cushion an object in more than one direction whenplaced within a shipping container.

Score lines (not illustrated in the drawings, but similar to score linesshown in webs of plastic film described in numerous ones of the priorU.S. patents incorporated by reference in this application) permit readydetachment of single ones or groups of inflated pillows from the film 19after the pillows are inflated and sealed.

A number of different film compositions (also as noted in U.S. patentsincorporated by reference in this application) can be used as thecomposition material for the web of film 19.

The machines that are used to preform the patterns on the web of film 19include conventional presses which impress multiple pillow patterns (andthe related ports and inflation channel) on a strip of film 19 on eachpressing operation. The pattern is formed while there is no inflationpressure anywhere in the web 19.

The preformed pattern can also be formed by a roller arrangement inwhich at least one roller is heated and configured to form the desiredpatterns.

Pattern forming machines of these kinds are also disclosed in several ofthe U.S. patents incorporated by reference in this application.

Such machines for forming preformed patterns in the film 19 can beassociated with the machine 11 shown in FIG. 1 to replace the storageroll 17 so that the preformed patterns can be preformed continuously atthe site where the machine 11 is installed. However, in most cases it ismore practical to use a storage roll 17 with preformed patterns than itis to preform the patterns at the job site where the machine 11 is to beused.

A second embodiment of a machine constructed in accordance with thepresent invention is illustrated in FIGS. 10-15 of the drawings. Thissecond embodiment is indicated by the general reference numeral 101.

The components and parts of the machine 101 which correspond to themachine 11 shown in FIGS. 1-9 are indicated by corresponding referencenumerals.

The machine 101 includes a cartridge unit 103 (see FIG. 12) which ismounted on a separate sub-plate or sub-frame 105. The sub-frame 105 ismounted on the main plate or main frame 13. This cartridge unittechnique permits the components of the entire cartridge unit to bequickly and easily interchanged (as a unit) with another replacementcartridge unit. Individual components of the cartridge unit do not haveto be removed and replaced.

In the machine 101 shown in FIGS. 10-15, the construction and mountingof the cartridge unit 103 permits the entire cartridge unit to be pulledout of a box and plugged in as a unit at the production site. Thiscartridge unit permits all of the components of the cartridge unit to bereplaced as a unit. It is never necessary, for example, to replace theNichrome wires as individual elements in the field. Instead, the entirecartridge unit is just pulled out and replaced as a unit with areplacement cartridge unit.

The structure, components and mode of operation of the first filmtransport station 27, the second film transport station 29, theinflation station 31, and the slitting station 35 are the same as thecorresponding mechanism, components and mode of operation describedabove with reference to the machine 11, and will not be reviewed in morespecific detail at this point.

The specific structure of the sealing station 33 of the machine 101 isdifferent from the machine 11 and will be described in more detailbelow. However, the method of making seals across the inlet ports 69 inthe machine 101 is the same as the method of machine 11, as will beunderstood from the description to follow.

One difference between the sealing station structure of the machine 11and the sealing station structure of the machine 101 is in the way thatthe heated sealing element and the sealing wheel are moved apart fromone another during those times when the machine is stopped betweenproduction runs of inflated pillows.

In the machine 11 (and as illustrated in FIG. 7) the heated sealingelement which is mounted on the end of the bar 81 is retracted away fromthe sealing wheel 75. In the machine 11 the shaft 75 of the heatedsealing wheel 75 is held in a fixed position with respect to the frame13 in all modes of operation of the machine 11.

In the machine 101 the heated sealing element is held in a fixedposition with respect to the frame 13. The rotational shaft 77 of thesealing wheel 75 is mounted for rotation in a movable support bracket 75so that the sealing wheel 75 is movable toward and away from the heatedsealing element.

As best illustrated in FIG. 13, the support bracket 75 is mounted on arod 82 of an actuator 84. The actuator 84 is mounted on a support plate86, and the support plate 86 is mounted on the main plate 13 of themachine 101.

The actuator 84 extends and retracts the rod 82 to move the sealingwheel 75 between the retracted position of the rod 82 shown in FIGS. 11and 15 and the extended position shown in FIGS. 10 and 14.

In the retracted position illustrated in FIGS. 11 and 15 the sealingwheel 75 is positioned to let the film 19 remain out of contact with theheated sealing element when the machine 101 is not operated in aproduction run.

In the extended position shown in FIGS. 10 and 14 the sealing wheel 75is positioned to engage the film 19 and to press that film 19 in slidingcontact with the heated sealing element as the film 19 is continuouslyand uninterruptedly advanced through the machine during a production runof inflated pillows.

In the extended position shown in FIGS. 10 and 14 the sealing wheel 75is positioned to engage the film 19 and to press that film 19 in slidingcontact with the heated sealing element as the film 19 is continuouslyand uninterruptedly advanced through the machine during a production runof inflated pillows.

The force with which the film 19 is engaged in sliding contact with theheated sealing element is determined by selecting the pressure levelwithin the actuator 84.

As best illustrated in FIGS. 12, 10, and 14, the cartridge unit 103comprises a guide block 107 mounted in a fixed position on the sub-plate105, two reels 109 and 111, each mounted for rotation on the sub-plate105, and a guide post 113 mounted on the sub-plate 105.

The reels 109 and 111 are storage and take-up reels for a strip ofcovering fabric 72. The fabric 72 has a Teflon coating on the sideengaged in sliding contact with the film 19.

The strip of covering fabric 72 is trained around a guide post 113 andinto the guide slots 115 and 117 which are recessed within the outer andforward surfaces of the flanges 119 and 121 of the guide block 107.

The way that the strip of covering fabric 72 is conveyed from thestorage roller 109, around the guide post 113, through the guide slot115, over the Nichrome wires 70, through the guide slot 117 and onto thereel 111 is best illustrated in FIGS. 10, 11, 14 and 15.

In a specific embodiment of the machine 101 the lower reel 111 isdriven, through reduction gearing, and by an electric motor (not shown),to pull the strip of covering fabric 72 across the Nichrome wires 70 ata relatively slow speed (a speed considerably slower than a speed atwhich the web of film 19 is transported through the machine 101 during aproduction run), but at a speed fast enough to insure that no part ofthe covering fabric 72 is ever in contact with the Nichrome wires 70long enough to permit any burn through of the fabric by the Nichromewires 70. The reel storage of the covering fabric 72 and the slowmovement of the fabric with respect to the Nichrome wires 70 duringoperation of the machine 101 thus insure that the area of the fabricengageable with the Nichrome wires is, in effect, renewed soon enough toprevent any burn through.

As best illustrated in FIGS. 12 and 15, the outer tips of the flanges119 and 120 extend slightly beyond the outer surfaces of the Nichromewires 70. This insures that the covering fabric 72 is engaged with theNichrome wires 70 only when the sealing wheel 75 is moved to theposition shown in FIGS. 10 and 14 during a production run of the machine101.

The strip of covering fabric 72 is held out of contact with the Nichromewires 70 when the machine 101 is not being operated in a production runof packaging.

While not illustrated in FIGS. 10-15, the Nichrome wires 70 areenergized by detachable leads 91 and 93 (as illustrated for the machine11 in FIGS. 9A-9G).

The sealing roller 75 of the machine 101 is laterally offset outwardlyin the same way as the sealing roller 75 of the machine 11 so as tocause a bump in the film 19 at the sealing station 33. This helps tocreate a dead zone adjacent the inlet port 69 to be sealed by causingthe web of film 19 to wrap around a part of the peripheral surface ofthe sealing roller 75 both in circumferential direction and also in alateral direction (as described above with reference to the machine 11).

The machine 101 permits sealing the inlet port at a sealing station byapplying a heated sealing element directly to and in sliding contactwith the web of film and across the inlet port while the air in aninflated pillow is under pressure and as the web of film is continuouslyand uninterruptedly advanced through each of the first transportstation, inflating station, sealing station, second transport stationand slitting station.

While we have illustrated and described the preferred embodiments of ourinvention, it is to be understood that these are capable of variationand modification, and we therefore do not wish to be limited to theprecise details set forth, but desire to avail ourselves of such changesand alterations as fall within the purview of the following claims.

1. A preconfigured plastic film for use in air-filled packing cushions,the film comprising: a longitudinally extending channel; a plurality ofgenerally rectangular inflatable chambers each having an unsealedopening into the longitudinally extending channel, wherein theinflatable chambers have heat seals forming a periphery of the chambersand secondary heat seals within the periphery; and a plurality oflaterally extending perforations separating each chamber or a pluralityof chambers, wherein the laterally extending perforations extend atleast partway across the width of the film.
 2. The preconfigured film ofclaim 1 wherein the inflatable chambers have three sides closed and afourth side with the unsealed opening into the longitudinally extendingchannel.
 3. The preconfigured film of claim 1 wherein the laterallyextending perforations extend the entire width of the film.
 4. Thepreconfigured film of claim 1 wherein the longitudinally extendingchannel extends along a longitudinal center portion of the film.
 5. Thepreconfigured plastic film of claim 1 wherein the film is formed from aflattened tube which provides a closed longitudinal edge.
 6. Thepreconfigured plastic film of claim 1 wherein a longitudinal edge of thefilm is closed by a heat seal.
 7. A preconfigured plastic film for usein air-filled packing cushions, the film comprising: a longitudinallyextending channel extending near an edge of the film; a plurality ofgenerally rectangular inflatable chambers each having an unsealedopening into the longitudinally extending channel, and preformed seallines within the interior of the chambers to permit the chambers to befolded along the seal lines; and a plurality of laterally extendingperforations separating each chamber or a plurality of chambers, whereinthe laterally extending perforations extend at least partway across thewidth of the film.
 8. The preconfigured film of claim 7 wherein theinflatable chambers have three sides closed and a fourth side with theunsealed opening into the longitudinally extending channel.
 9. Thepreconfigured film of claim 7 wherein the laterally extendingperforations extend the entire width of the film.
 10. The preconfiguredfilm of claim 7 wherein the film is formed from a flattened tube whichprovides a closed longitudinal edge.
 11. The preconfigured plastic filmof claim 7 wherein a longitudinal edge of the film is closed by a heatseal.